Research Reports - The impact and prospect of traumatic brain injury on olfactory function

Eur Arch Otorhinolaryngol. 2013 Sep 27

Gudziol V, Hoenck I, Landis B, Podlesek D, Bayn M, Hummel T

Traumatic brain injury (TBI) can cause olfactory loss. The aim of this
cross-sectional and prospective study was to determine the prevalence of
olfactory loss among 110 patients with TBI within 3 months after the trauma. In
81 patients ("cross-sectional"-group), olfactory function could be measured using
the validated "Sniffin' Sticks" test for odor threshold and odor identification.
In addition, the prospective change of olfactory function was studied in 36
patients ("follow-up"-group) by means of a validated odor threshold,
discrimination and identification test. Olfactory function was significantly
better in patients with TBI I° compared to individuals with TBI II° and III°.
Clinically significant improvement of olfactory function was found in 36 % of the
patients, most frequently during the first 6 months after the injury, in a median
follow-up interval of 21 months. TBI I° has in general no major effect on
olfaction. In contrast, patients with TBI II° and III° exhibit smell loss in
57 %. Chances for olfactory recovery were highest within the first 6 months after
the trauma.